Problem: Simplify the following expression: $n = \dfrac{2p}{5} + \dfrac{p}{7}$
In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $5$ and $7$ $\lcm(5, 7) = 35$ $ n = \dfrac{7}{7} \cdot \dfrac{2p}{5} + \dfrac{5}{5} \cdot \dfrac{p}{7} $ $n = \dfrac{14p}{35} + \dfrac{5p}{35}$ $n = \dfrac{14p +5p}{35}$ $n = \dfrac{19p}{35}$